During the academic year 2015-2016, I organized the weekly seminar Groups, Actions and von Neumann algebras at the Université Paris-Sud, Orsay. This seminar featured both research and introductory talks.

Meetings

Thursday October 8

Amaury Freslon (Université Paris-Sud)

Introduction to C*-simplicity for discrete groups

Thursday October 22

Amine Marrakchi (ENS Paris and Université Paris-Sud)

Furstenberg and Hamana boundaries of discrete groups (Part I)

Thursday November 12

Amine Marrakchi (ENS Paris and Université Paris-Sud)

Furstenberg and Hamana boundaries of discrete groups (Part II)

Cyril Houdayer (Université Paris-Sud)

C*-simplicity and the unique trace property for discrete groups (after Breuillard-Kalantar-Kennedy-Ozawa) (Part I)

Thursday November 19

Cyril Houdayer (Université Paris-Sud)

C*-simplicity and the unique trace property for discrete groups (after Breuillard-Kalantar-Kennedy-Ozawa) (Part II)

Thursday November 26

Arnaud Brothier (Vanderbilt University)

Approximation properties and subfactors

Thursday December 3

Yves de Cornulier (CNRS and Université Paris-Sud)

Groups of tree automorphisms with an almost everywhere prescribed action

Thursday December 17

Yuhei Suzuki (The University of Tokyo)

Minimal ambient nuclear C*-algebras

Thursday January 7

Cyril Houdayer (Université Paris-Sud)

Bi-exact groups, strongly ergodic actions and group measure space type III factors with no central sequence

Thursday January 21

Romain Tessera (CNRS and Université Paris-Sud)

A functional analysis proof of Gromov’s polynomial growth theorem (after Ozawa) (Part I)

Monday January 25

Romain Tessera (CNRS and Université Paris-Sud)

A functional analysis proof of Gromov’s polynomial growth theorem (after Ozawa) (Part II)

Monday February 1

Jean Lécureux (Université Paris-Sud)

Bader-Shalom’s normal subgroup theorem (Part I)

Monday February 8

Jean Lécureux (Université Paris-Sud)

Bader-Shalom’s normal subgroup theorem (Part II)

Monday February 29

Koichi Shimada (The University of Tokyo)

Examples of maximal amenable subalgebras in free group factors arising from irrational rotation algebras

Monday March 14

Rémi Boutonnet (CNRS and Institut de Mathématiques de Bordeaux)

II_1 factors with non-isomorphic ultrapowers

Monday March 21

Sven Raum (WWU Münster)

C*-simple and non-C*-simple locally compact groups

Monday April 4

Camille Horbez (CNRS and Université Paris-Sud)

An introduction to Out(Fn)

Monday April 11

Camille Horbez (CNRS and Université Paris-Sud)

The Poisson boundary of Out(Fn)

Monday June 20

Hiroshi Ando (Chiba University)

Unitarizability, Maurey-Nikishin factorization and Polish groups of finite type